DESCRIPTION (Applicant's abstract): Assessment procedures for the personality disorders (PDs) typically focus on self-report measures, even though some people with PDs may be unable to view themselves realistically or unwilling to report socially undesirable traits. Close associates may provide important information regarding the presence of PD traits. Peer nomination is reliable and valid assessment procedure that can be adapted to the study of PDs for research purposes. The proposed study will focus on characteristic features which define ten DSM-IV personality disorders using information collected from both self and others in non-clinical samples of adult men and women. The study is designed to accomplish three major goals: 1) to identify specific areas of agreement and discrepancy between self-report and peer assessment in the measurement of characteristic features of these disorders, 2) to compare the ability of the self- and other-reports to predict the presence of PDs (as determined by structured clinical interviews conducted with a subset of the subjects), and 3) to construct new self-report scales that are better able to predict peer assessments of pathological traits. We will screen an initial sample of 3,000 subjects (1,500 US Air Force recruits and 1,500 university students; half of each group male). In the first assessment phase, each subject will complete a 100-item peer nomination inventory (PNI) describing members of their group, and the Schedule of Nonadaptive and Adaptive Personality (SNAP; Clark, 1990). The second assessment phase will involve diagnostic interviews with 15% of these subjects (150 who were rated highest by their peers on the PNI, 150 who were rated highest by themselves of the SNAP, and 150 selected at random). Interviews will be conducted following the Structured Interview for DSM-IV Personality (SIDP) by trained clinicians who are blind to all information from the pre-screening procedure.